Heat transfer systems are used to transport heat from one location (the heat source) to another location (the heat sink). Heat transfer systems can be used in electronic equipment, which often requires cooling during operation.
Loop Heat Pipes (LHPs) and Capillary Pumped Loops (CPLs) are examples of two-phase loop heat transfer systems. Each of these systems includes an evaporator thermally coupled to the heat source, a condenser thermally coupled to the heat sink, fluid that flows between the evaporator and the condenser, and a fluid reservoir for expansion of the fluid. The fluid within the heat transfer system can be referred to as the working fluid. The evaporator includes a wick and a core that includes a fluid flow passage. Heat acquired by the evaporator is transported to and discharged by the condenser.
These systems utilize capillary pressure developed in a fine-pored wick within the evaporator to promote circulation of working fluid from the evaporator to the condenser and back to the evaporator. These systems may further include a mechanical pump that helps recirculate the fluid back to the evaporator from the condenser.